Abstract: As a three-dimensional structure, the transverse and longitudinal characteristics of a shield tunnel are closely correlative. Although it simplifies the three-dimensional problem by separating it into two plane problems, the relationship between the transverse and longitudinal characteristics cannot be taken into account in the analysis process. On the basis of the amendatory habitual analytical method, the longitudinal equivalent rigidity is deduced by considering the introduced transverse rigidity efficiency in the longitudinal equivalent continuous model. As a result, the formula to calculate longitudinal equivalent rigidity is gotten, which unifies the transverse and longitudinal characteristics of the shield tunnel and also demonstrates their correlation and matching. The practical analysis shows that the longitudinal equivalent rigidity increases with the increase of the transverse rigidity in a nearly linear relation.